Patent Literature 1 discloses a semiconductor device in which an external electrode which is a copper plate and a semiconductor element electrode are directly joined to each other through solder. The external electrode and the semiconductor element electrode are directly joined through solder for the purpose of realizing wiring connection capable of large-current energization while having reduced electrical resistance.
Patent Literature 2 discloses forming a metal film (plating electrode) on a portion of a semiconductor element electrode (emitter electrode), the metal film having good connection to solder. This metal film is joined to a heat sink through solder. Concentration of stress in a peripheral end portion of the metal film is prevented by controlling the distance and the relative position between the metal film and the heat sink.